Formula To Calculate The Expansion Vessel Pre-Pressure; To Check The Water Volume And Flow Rate - Daikin EBLA09D V3 Series Installer's Reference Manual

8 | Piping installation

8.1.2 Formula to calculate the expansion vessel pre-pressure

8.1.3 To check the water volume and flow rate

Installer reference guide
76
▪ Domestic hot water tank – Standstills. In cases where during longer periods of
time there is no consumption of hot water, the equipment MUST be flushed with
fresh water before usage.
▪ Domestic hot water tank – Disinfection. For the disinfection function of the
domestic hot water tank, see
4
disinfection" [ 51].
▪ Thermostatic mixing valves. In accordance with the applicable legislation, it may
be necessary to install thermostatic mixing valves.
▪ Hygienic measures. The installation must be in compliance with the applicable
legislation and may require additional hygienic installation measures.
▪ Recirculation pump. In accordance with the applicable legislation, it may be
required to connect a recirculation pump in between the hot water end point
and the recirculation connection of the domestic hot water tank.
a b
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
The pre-pressure (Pg) of the vessel depends on the installation height difference
(H):
Pg=0.3+(H/10) (bar)
The outdoor unit has an expansion vessel of 8 litre with a factory-set pre-pressure
of 1 bar.
To make sure that the unit operates properly:
▪ You MUST check the minimum and maximum water volume.
▪ You might need to adjust the pre-pressure of the expansion vessel.
Minimum water volume
Check that the total water volume in the installation is higher than the minimum
water volume, the internal water volume of the outdoor unit NOT included:
If...
Cooling operation
Heating/defrost operation and...
"11.6.6 Tank" [
c
d
4
177] and "6.4.5 DHW pump for
Then the minimum water volume
is...
20 l
EBLA09~16D + EDLA09~16D
Daikin Altherma 3 M
4P620241-1B – 2022.05